This invention generally relates to tamper-evident seals, and in particular to tamper-evident seals having a surface for the display of an identifying mark, typically a serial number, and having, furthermore, a weak section that is lockably held by a catch-mechanism, this weak section irreversibly breaking when access or entry is sought into the space to the portal of which the seal has been protectively affixed. Tamper-evident seals frequently are used to deter entry by persons who, in at least some circumstances, of which it is desired to limit the number and kind, may actually seek entry validly and justifiably.
In one, commonly-met arrangement, metal anchorages equipped with apertures--such as a pair of welded eyebolts, or a pair of right-angle plates with bored apertures, etc.--are mounted, one apiece, on a door and door frame. A tamper-evident seal is then passed through each of the apertures, whereupon the seal is clasped together, it's weak section now lockably held by its catch. To open the door, the seal must either be broken or the seal's catch-mechanism must be defeated without, however, leaving visible evidence of an unauthorized entry.
Often, tamper-evident seals are molded out of thermoplastics such as polypropylene, and cost, exclusive of amortized mold costs, a few pennies apiece. Tamper-evident seals are thus considerably more economical than electronic security devices and, very often, are more cost-effective, as well. The above-mentioned, identifying marks typically are hot-stamped onto, or are embossed, or cast directly, into the seals' thermoplastic material. Tamper-evident seals made variously out of wax, metal, ceramic or even of paper elements have been in widespread use since antiquity.
A disadvantage of nearly all tamper-evident seals is that, upon breakage of the seal, the entire seal becomes discardable waste. Were some functional part of the seal to be made reusable, however, then a supply of such seals, as might be packaged with a consumer product, would require considerably less packaging than a supply of seals destined over time to be discarded entirely. Since waste-reduction marginally reduces production costs and externalizes a smaller recycling load, such savings are clearly desirable. Since reduced packaging-space roughly translates into reduced, end-user, storage space, end-user, product appeal is enhanced, as well. This is true most especially for a society that is awash in manufactured "goods".
A tamper-evident seal that provides a single opportunity for reuse is taught by U.S. Pat. No. 5,522,627 (Swift; Jun. 4, 1996). The reusability of this seal, however, although doubtless of advantage in certain circumstances, does not appear to be especially advantageous either for discouraging and/or for deterring and/or preventing unauthorized entry into a seal-protected space. The party desiring to control entry may simply fail to notice that a seal so subtly constructed had been reused.
A readily identifiable, multiply-reusable, tamper-evident seal would therefore appear to have some general utility. Such a seal might be usefully combined with an existing security product in order to enhance that product's appeal. One example of such a product is the anti-snooping device for apartment dwellers disclosed by U.S. Pat. No. 5,875,660 (Olshausen; Mar. 2, 1999).